Related Experiment Videos
Heparin-induced thrombocytopenia-associated thrombosis in pediatric intensive care patients
Markus Schmugge1, Lorenz Risch, Andreas R Huber
1Division of Hematology/Oncology, Hospital for Sick Children, Toronto, Ontario, Canada. m.schmugge@freesurf.ch
Insights
Heparin-induced thrombocytopenia (HIT) with thrombosis occurs in 2.3% of pediatric intensive care unit patients exposed to heparin. Outcomes in children are generally less severe than in adults.
Area of Science:
- Pediatric Intensive Care Medicine
- Hematology
- Pharmacology
Background:
- Heparin-induced thrombocytopenia (HIT) is a known heparin therapy complication.
- HIT occurs in 1-5% of adult heparin users, with 29-88% developing thrombosis.
- Pediatric data on HIT-associated thrombosis are limited.
Purpose of the Study:
- To determine the incidence of HIT-associated thrombosis in pediatric intensive care unit patients exposed to heparin.
- To compare the severity of HIT-associated thrombosis in children versus adults.
Main Methods:
- Retrospective cohort study of pediatric intensive care unit patients receiving heparin for >/=5 days.
- Radiological confirmation of thrombosis and review for clinical HIT criteria.
- Serological confirmation of HIT-associated thrombosis via antibody testing.
Main Results:
- Of 612 heparin-exposed children, 57 (9.3%) developed thrombosis.
- HIT-associated thrombosis incidence was 2.3% (95% CI: 1.3%-3.9%).
- Nine patients had venous, 2 arterial, and 3 combined thrombosis; outcomes were less severe than in adults.
Conclusions:
- HIT-associated thrombosis incidence in pediatric intensive care units is similar to adults.
- Outcomes of HIT-associated thrombosis appear less severe in pediatric patients compared to adults.
Background:
Heparin-induced thrombocytopenia (HIT), a well-known side effect of heparin therapy, occurs in 1% to 5% of adults exposed to heparin. Of those, about 29% to 88% develop thrombosis. Most data on HIT-associated thrombosis in children are confined to anecdotal reports.
Objective:
To determine the incidence of HIT-associated thrombosis in heparin-exposed children.
Methods:
We performed a retrospective cohort study on all patients admitted to our pediatric intensive care unit between August 1996 and January 1999. Patients who received heparin for >/=5 days were eligible. Within these patients, we identified all cases of radiologically confirmed thrombosis. Cases of thrombosis were reviewed for fulfillment of clinical HIT criteria. HIT-associated thrombosis was confirmed serologically by determination of levels of antibodies against heparin/platelet factor 4 complexes.
Results:
Of 1950 children admitted during the study period, 612 were exposed to heparin for >/=5 days. Thrombosis occurred in 57 patients (9.3%). Plasma samples were available for 38 cases, of which 14 satisfied clinical HIT-criteria. Calculated incidence rate for HIT-associated thrombosis: 2.3%, (95% confidence interval: 1.3%-3.9%, for patients exposed to heparin >/=5 days). Nine patients suffered from venous, 2 patients from arterial, and 3 had combined arterial and venous thrombosis. None of the 14 patients died or underwent amputation. Six patients had heparin and platelet factor 4-complex antibody levels above the cutoff level for adults. The remaining 8 patients had significantly higher antibody levels than a matched control group.
Conclusion:
Compared with that reported for adults, HIT-associated thrombosis in pediatric intensive care unit patients has a similar incidence but a less severe outcome.